The FBI wants Apple to unlock an iPhone belonging to one of the people behind December's mass shooting in San Bernardino, California. Apple says it's taking a stand for privacy rights, while the FBI says it's merely trying to conduct the most thorough investigation possible.

An enormous rooftop greenhouse on Chicago's South Side is growing crops year-round and providing the area with much-needed local produce. Joining us to talk about Gotham Greens' growing power is co-founder and CEO, Viraj Puri.

The detection of gravitational waves first predicted by Albert Einstein is being hailed as one of the most important discoveries of the modern age. Some local scientists who worked on this groundbreaking achievement are here to explain.

A viewer's video, shared with "Chicago Tonight," shows his encounter with a coyote in Columbus Park while walking his two dogs. Coyote mating season has begun, which means the urban animals may behave aggressively.

Scientists at the University of Chicago are hoping a new, highly sensitive camera they're developing for the South Pole Telescope will reveal new information about the early universe. The camera measures something that's nearly 14 billion years old: radiation left over from the Big Bang.

Project Nearly 90 Years in the Making

The onset of the Great Depression stalled a nearly complete diorama project conceived in the 1920s. Emily Graslie, the Field's chief curiosity correspondent, made it her mission to complete it nearly 90 years later. She joins us to discuss the project.